DPPH free radical scavenging

Abstract Recently, we have investigated Aconitum cochleare Woroschin and obtained three new alkaloids cochleareine, acoleareine from the aerial parts of the plant and cochleareinine from the roots. Cochlearenine exhibited antioxidant activity against DPPH free radical scavenging assay. The cardio active effect of has also have been studied on isolated heart preparations. 

Jothy ST, Zuraini Z, Sasidharan S. Phytochemicals screening, DPPH free radical scavenging and xanthine oxidase inhibihory activihes of Cassia fistula seeds extract. Journal of Medicinal Plants Research. 2011 5(10) 1941-1947. 

Most stilbenoids possess antioxidant activities because they possess polyphenol functions in the molecules. Some of their beneficial effects, hepatoprotective action, cardiovascular protection, for instance, are in close relation to their antioxidant activities. Several models have been employed in the assay such as lipid peroxidation system, human low-density lipoprotein model, xanthine oxidase system and l,l-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging model, which is the most commonly used protocol. 

Antioxidant activity of petroleum ether, chloroform, ethyl acetate and methanol extracts of Usnea pictoides lichen was determined by DPPH free radical scavenging assay and ferric reducing assay (Pavithra et al. 2013). The scavenging potential of methanol extract was higher than other extracts, and also, in ferric reducing assay, methanol extract showed stronger reducing power than other extracts. 

Chandrasekar, D., K. Madhusudhana, S. Ramakrishna, and P. V. Diwan. 2006. Determination of DPPH free radical scavenging activity by reversed-phase HPFC A sensitive screening method for polyherbal formulations. Journal of Pharmaceutical and Biomedical Analysis 40(2) 460-464. 

The aqueous and ethyl acetate flower extracts rich in luteolin and luteolin-7-gluco-side exhibited antioxidant activity in the 2,2-iphenyl-l-picrylhydrazyl (DPPH) free radical scavenging assay as well as in the phosphatidylcholine liposome assay. Lower concentrations, however, had a pro-oxidant effect. 

FREE RADICAL SCAVENGING ACTIVITY 15.4.1 DPPH Free Radical Scavenging Activity... 

Measurement of DPPH Free Radicals Scavenge Activity... 

The antioxidant activity of the four phytochemicals isolated from rosemary were assayed in a DPPH free radical scavenge system. Carnosic acid, camosol and rosmarinic acid showed concentration-dependent scavenging ability. These phytochemicals were more potent than vitamin C and vitamin E. The 50% DPPH... 

In the present study, carnosol, camosic acid and rosmarinic acid showed effective DPPH free radicals scavenging activity. Camosic acid, carnosol, rosmarinic acid and ursolic acid effectively inhibited pUC19 DNA strand break induced by Fenton reaction (28). The reaction of iron (II) with hydrogen peroxide is generally considered to yield the hydroxyl radicals (29). These compounds may react with and/or scavenge the hydroxyl radicals produced by Fenton reaction. 

In this study, we used a DPPH free radical scavenging activity directed identification process to pinpoint the antioxidants from the dried bark of Du-zhong and to elucidate their chemical structures as well as to compare their antioxidant capacities. 

The 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) method was used to investigate the scavenging activity of tea samples. The data for DPPH free radical scavenging activity, measured as scavenging percentage at room temperature after addition of various fermented tea infiisions are presented in Figure 3. DPPH free radical scavenging activity of tea infusion inoculated with A. aceti and A. xylinum increased with incubation time up to 22.1% and 21.9%,... 

Nand et al. (2012) have observed very good DPPH free radical scavenging properties of the polyaniline/ PE blends [23]. The free radical... 

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